CVE-2022-50484 in Linux
Summary
by MITRE • 10/04/2025
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Fix potential memory leaks
When the driver hits -ENOMEM at allocating a URB or a buffer, it aborts and goes to the error path that releases the all previously allocated resources. However, when -ENOMEM hits at the middle of the sync EP URB allocation loop, the partially allocated URBs might be left without released, because ep->nurbs is still zero at that point.
Fix it by setting ep->nurbs at first, so that the error handler loops over the full URB list.
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Analysis
by VulDB Data Team • 03/01/2026
The vulnerability identified as CVE-2022-50484 resides within the Linux kernel's Advanced Linux Sound Architecture ALSA subsystem, specifically within the usb-audio driver component. This flaw represents a memory management issue that occurs during the initialization process of USB audio devices, where the driver attempts to allocate Universal Resource Blocks for handling audio data transfers. The vulnerability manifests when the system encounters memory allocation failures during the setup of synchronous endpoint URBs, which are critical for maintaining proper audio streaming functionality between USB audio devices and the host system.
The technical root cause of this vulnerability stems from improper resource management during error handling within the USB audio driver's initialization sequence. When memory allocation fails at an intermediate point in the synchronous endpoint URB allocation loop, the driver's error handling mechanism fails to properly release all previously allocated resources. This occurs because the ep->nurbs counter, which tracks the number of successfully allocated URBs, remains set to zero during the error path execution. As a result, the cleanup routine cannot iterate through the complete list of allocated URBs, leaving some memory segments in an unreleased state. This memory leak pattern represents a classic resource management flaw that can accumulate over time and potentially lead to system instability or denial of service conditions.
The operational impact of this vulnerability extends beyond simple memory consumption issues, as it can compromise system stability and resource availability in environments where USB audio devices are frequently connected and disconnected. The memory leaks can accumulate during repeated device initialization attempts, particularly in systems with high device turnover or automated device management processes. Attackers who can trigger this condition repeatedly might be able to exhaust available memory resources, leading to system performance degradation or complete system hangs. This vulnerability particularly affects systems running Linux kernels where USB audio devices are actively used, including servers, desktop environments, and embedded systems with audio capabilities.
Mitigation strategies for CVE-2022-50484 focus on applying the kernel patch that corrects the resource management logic by ensuring that the ep->nurbs counter is properly initialized before entering the allocation loop. This fix ensures that when memory allocation fails, the error handler can properly iterate through all previously allocated URBs and release them appropriately. System administrators should prioritize updating their Linux kernel versions to include this fix, particularly in production environments where USB audio devices are critical components. The vulnerability aligns with CWE-401, which addresses improper resource management, and could potentially be leveraged in combination with other memory-related attack vectors to create more sophisticated exploitation scenarios. Regular kernel updates and proper system monitoring for memory consumption patterns should be implemented as part of comprehensive security operations to prevent exploitation of this and similar memory management vulnerabilities.